Process of making phenylalanine-free food for infants and small children

ABSTRACT

A phenylalanine-free nutrient base for infants and small children, sad also a process for the production thereof, are provided. This nutrient base, in addition to an amino acid mixture which has all L-amino acids necessary for the nutrition of the child, except for phenylalanine, also contains fats sad/or carbohydrates sad also, optionally, minerals and/or trace elements. This nutrient base is produced by spray-drying of an aqueous formulation containing these components. During this, at least the amino acids lysine and cystine are at least in part mixed into the spray-dried product obtained after the spray-drying. Owing to the fact that these amino acids are not spray-dried with the others, the end product obtained is free of undesired by-products that form during spray-drying.

The invention concerns a process for the production of aphenylalanine-free nutrient base for infants and small children, whichin addition to an amino acid mixture which has all L-amino acidsnecessary for the nutrition of the child, except for phenylalanine, alsocontains fat(s) and/or carbohydrates and also, optionally, mineralsand/or trace elements, wherein an aqueous formulation containing thesecomponents is spray-dried.

Phenylketonuria (referred to below as PKU) is among the geneticallydetermined diseases, and is a metabolic disorder. For treatment of thismetabolic disorder, a child suffering from PKU normally receives a foodwhich contains a limited amount of natural protein and just so muchphenylalanine as the child's body needs for building up protein(growth).

However, such a low phenylalanine diet alone would provide the childrenwith too little of all other amino acids, just as important for life.Hence these children are given special products, which are mixtures ofL-amino acids or of specific extremely low-phenylalanine proteins orprotein hydrolysates. In addition, vitamins, minerals and trace elementsare incorporated in these mixtures.

Now the diet of an infant suffering from PKU consists of a bottle-food,which is made up of adapted infant milk-food and/or breast milk and aphenylalanine-free infant nutrient base.

Such a phenylalanine-free nutrient base for infants and small childrenis known from German patent application P 40 42 115.5 and Europeanpatent application EP-A 0 492 138. In these publication, the problemsconnected with PKU and its treatment are explained in more detail.Reference is thus expressly made to the disclosures of thesepublications.

In the production of the phenylalanine-free nutrient bases for infantsand small children nutrient bases described in the aforesaid twopublications, the amino acids, which are mainly used as free acids,together with the other constituents, for example fats andcarbohydrates, etc., are incorporated into an aqueous formulation, whichis then spray-dried.

In the spray-drying of these known, complete nutrient bases which arebased on amino acids, the problem then arose that chemical reactionstook place, so that the amino acid analysis of the final productdeparted from the values theoretically to be expected, and undesiredbyproducts arose. Hence the aim of the present invention is to provide aprocess for the production of a nutrient base for infants and smallchildren and such a nutrient base itself which can be obtained byspray-drying, where during this spray-drying as few undesiredby-products as possible arise or are formed.

This aim is achieved by the teaching of claim 1 and claim 8respectively.

It has now surprisingly been found that a phenylalanine-free nutrientbase for infants and small children which contains as few by-products aspossible can be obtained by spray-drying of an aqueous formulation, ifat least the amino acids lysine and cystine are at least in part notspray-dried with this formulation, but are mixed with or added into thespray-dried product later.

According to the invention, the whole amount of the amino acids lysineand/or cystine can be mixed with the already spray-dried product.However it is also possible to add part of the lysine and/or cystine tothe wet formulation to be spray-dried, and then only later to mix in theremainder dry. Here the amount of lysine and/or cystine which is addedto the wet formulation to be spray-dried should not make up more than10% of the total amount of lysine and/or cystine used.

Hence it is sufficient according to the invention to "leave out" onlyone of the two amino acids lysine and cystine during the spray-dryingand only later mix it in dry. In this case also, up to 10% of the totalamino acid lysine or cystine used can be subjected to the spray-dryingprocess. With this procedure, fewer undesired by-products already arisethan in the product according to the state of the technology.Preferably, however, both amino acids lysine and cystine are left outduring the spray-drying and only mixed in later.

Further, it is possible to mix small part amounts of one or more of theother amino acids into the spray-dried product. However this part amountshould make up not more than 5% of the total amino acid used.Preferably, however, all amino acids except for lysine and cystine areadded to the wet formulation to be spray-dried, however during this asmall part of the lysine can be added for complexing the metals (e.g.for Cu(II)SO₄).

Here the lysine is preferably mixed into the already spray-dried productin the form of the glutamate and thus as lysine glutamate. Hence theglutamic acid is also in part only mixed in after the spray-drying.

If now the amino acids L-cystine and L-lysine are mixed according to theinvention after the spray-drying into the product obtained therefrom,then undesired by-products are no longer formed and the amino acidanalysis corresponds to that specified.

Also subject matter of the invention is a phenylalanine-free nutrientbase for infants and small children, which can be obtained by theprocess according to the invention and hence can be produced in thisway.

The advantages from the nutritional point of view obtainable with thenutrient base obtainable according to the invention correspond to thoseadvantages which are described in EP-A 0 492 138, to which reference isexpressly made.

The amino acids can be present in the nutrient base obtainable accordingto the invention in any suitable form, particularly in any formpermissible for foodstuff purposes. Thus the amino acids can for examplebe present as salts, hydrochloride, hydrates, acetates, and malates,etc. Further, they can be used in the form of glutamates and aspartates.It is also possible to use the amino acids in the form of short-chainpeptides, particularly dipeptides, provided that these peptides containno phenylalanine.

In the nutrient base obtainable according to the invention, the aminoacid pattern is preferably matched to that in adapted conventional foodsand/or in human milk, the phenylalanine of course being left out of theformula.

As fats, carbohydrates, minerals, trace elements and vitamins, thosewhich were already used in the known phenylalanine-free spray-driednutrient base can be used. Here the fats can be mixtures of vegetableand/or animal fats and/or oils.

In the production of the aqueous formulation to be spray-dried, thestarting point is preferably cold water (8° to 20° C.), in which theamino acids, the carbohydrates, the minerals and/or the trace elementsare dissolved, dispersed or emulsified. A fat mixture to be incorporatedinto the wet formulation is prepared separately, and this is thenincorporated or metered into the wet formulation before thespray-drying.

The process according to the invention and the phenylalanine-freenutrient base for infants and small children are explained in moredetail in the following example.

1,425 kg cold (15° C.) water are taken, and to this are successivelyadded:

    ______________________________________                                        kg          Component                                                         ______________________________________                                        158.5       instant starch                                                    449.3       lactose EP                                                        7.73        aspartic acid                                                     23.52       L-glutamic acid                                                   15.98       L-isoleucine                                                      1.70        L-leucine                                                         20.13       L-tyrosine                                                        0.17        L-proline                                                         12.70       L-threonine                                                       14.01       L-serine                                                          11.17       L-alanine                                                         16.97       L-valine                                                          6.57        L-glycine (sic)                                                   6.13        L-methionine                                                      6.57        L-histidine                                                       10.06       L-arginine                                                        4.60        L-tryptophan                                                      17.47       calcium carbonate                                                 18.19       calcium glycerophosphate                                          17.49       magnesium L-aspartate                                             346.9       MDO2 (maltodextrin degradation level 2)                           0.83        vanillin                                                          ______________________________________                                    

Next this aqueous formulation is heated to 70° C. Then the followingminerals, etc., which had previously been dissolved, alone or several atonce, in the necessary amount of water, are added:

    ______________________________________                                        kg             Component                                                      ______________________________________                                        1.831          potassium chloride                                             10.90          sodium chloride                                                0.0012         potassium iodide                                               0.0072         sodium fluoride                                                15.56          dipotassium hydrogen phosphate                                 5.36           potassium carbonate                                            1.4851         sodium carbonate                                               0.0428         vitamin C                                                      0.0660         L-lactic acid                                                  0.4032         iron-(II) sulphate                                             0.2436         zinc sulphate*                                                 0.0304         copper-(II) sulphate**                                         0.232          manganese sulphate***                                          0.0020         sodium molybdate                                               0.0020         chromium-(III) chloride                                        1.092          taurine                                                        0.1984         L-carnitine                                                    0.2184         myoinositol                                                    4.6            choline hydrogen tartrate                                      ______________________________________                                         *The zinc sulphate was dissolved in 5 l water with addition of 0.0376 kg      Lhistidine and then added.                                                    **The copper(II) sulphate was dissolved in 5 l water with addition of         0.0396 kg Llysine and then added.                                             ***The manganese sulphate was dissolved in 5 l water with addition of         0.0380 kg Lhistidine and then added.                                     

The amino acids added during the dissolution of the said metal salts arefor the purpose of complexing.

The mixture so produced has a volume of ca. 1,600 l.

609 kg fat mixture are added to this aqueous mixture; the preparation ofthis fat mixture is described below. Next the wet formulation ishomogenised (1st stage 150 bar, 2nd stage 50 bar). The wet formulationis then heated to 90° C., again homogenised and dried in a spray-tower.The drying can be carried out with a spray-disc and with nozzles. Thewet formulation is preferably dried with nozzles.

    ______________________________________                                        Conditions:                                                                   ______________________________________                                        Entry temperature:   170 to 190° C.                                    Exit temperature:    85 to 95° C.                                      Nozzle pressure:     150 to 170 bar                                           ______________________________________                                    

The product obtained after the spray-drying can be filled intocontainers.

The following components are added per 400 kg of the product soobtained:

    ______________________________________                                        kg              Component                                                     ______________________________________                                        15.82           lysine-l-glutamate triturate                                  1.429           L-cystine                                                     3.062           vitamin mix                                                   103.3           lactose EP                                                    ______________________________________                                    

After this, it is mixed for ca. 20 mins. The finished end product or thenutrient base so produced can then be filled (into containers).

The procedure for the preparation of the above fat mixture is asfollows:

565 kg fat (80% palm oil, 10% soya oil (or maize oil), 10% coconut oil)are pumped into a fat mixing tank and heated to 700° C. 8.57 kg purelecithin and 0.72 kg Tegomuls 90 S (mixture of mono- and diglycerides)are then added and (the mixture) is stirred.

When amino acids are mentioned in the present documents, L-amino acidsare meant. Unless otherwise stated, all % statements refer to wt %.

We claim:
 1. Process for the production of a phenylalanine-free nutrientbase for infants and small children, which in addition to an amino acidmixture which has all L-amino acids necessary for the nutrition of thechild except for phenylalanine, also contains fat(s) and/orcarbohydrates and also optionally minerals and/or trace elements,wherein an aqueous formulation containing these components isspray-dried, characterised in that:at least the amino acids lysine andcystine are at least in part mixed dry into the product obtained afterthe spray-drying.
 2. Process according to claim 1,characterised in that:the amino acids are used in such an amount that with the exception ofphenylaianine the amino acid pattern of the product obtained is matchedto that in normal adapted foods and/or in human milk.
 3. Processaccording to claim 1,characterised in that: the components are used insuch amounts that the amino acids make up 5-20%, the fats 10-30% and thecarbohydrates up to 70%, each based on the dry mass of the product, andthat the amount and the nature of the minerals and the trace elementscorrespond to the recommendations and guidelines for foods for infantsand small children.
 4. Process according to claim 1,characterised inthat: the components are dissolved, dispersed or emulsified in coldwater, and the wet formulation so obtained is heated, homogenised andoptionally pasteurised in particular at 70° to 90° C. beforespray-drying.
 5. Process according claim 1,characterised in that: thespray-drying is performed in an atomiser equipped with nozzles, withdrying and simultaneous agglomeration.
 6. Process according to claim1,characterised in that: vitamins are also added.
 7. Process for theproduction of a phenylalanine-free nutrient base for infants and smallchildren, which in addition to an amino acid mixture which has allL-amino acids necessary for the nutrition of the child except forphenylalanine, also contains fat(s) and/or carbohydrates and alsooptionally minerals and/or trace elements, wherein an aqueousformulation containing these components is spray-dried,characterized inthat: at least the amino acids lysine and cystine are at least in partmixed dry into the product obtained after the spray-drying; and theamino acids are mainly used as free acids.
 8. Process according to claim7,characterized in that: the components are used in such amounts thatthe amino acids make up 5-20%, the fats 10-30% and the carbohydrates upto 70%, each based on the dry mass of the product, and that the amountand the nature of the minerals and the trace elements correspond to therecommendations and guidelines for foods for infants and small children.9. Process according to claim 7,characterized in that: the componentsare dissolved, dispersed or emulsified in cold water, and the wetformulation so obtained is heated, homogenized and optionallypasteurized in particular at 70° to 90° C. before spray-drying. 10.Process according to claim 6 characterized in that water and fat-solublevitamins are also added.
 11. Process according to claim 6 characterizedin that the amino acid is lysine glutamate.